Control means for heating systems



Feb. 2, 1954 E. B. TIDD CONTROL MEANS EoR HEATING sYsTEMs Filed Aug. 8, 1950 6 Shee'ts-Sheet l d' O ,w @mg T /W M U E N, w. N N. IMEI RMV r///////W\\\\ KTQ/f1 l. N. .mw h) wt xx. .MIM MN NM MM EN www EN .i N @NNI Nn w XI k\l .NXI Lft' .m lm Il! EN SW Q N0 N EN N Feb. 2, 1954 E. B. TIDD 2,568,216 CONTROL MEANS FOR' HEATING SYSTEMS Filed Aug. 8. 1950 A6 Sheets-Sheet 2 www Feb. 2, 1954 E. B. 'non 2,668,216

CONTROL MEANS FOR HEATING SYSTEMS y Filed Aug. 8, 1950 6 Sheets-Sheet 3 E. B. TIDD CONTROL MEANS FOR HEATING SYSTEMS Feb. 2, l 1954 6 Sheets-Sheet 4 Filed Aug. 8, 1950 Feb. 2, 1954 E. a. TIDD CONTROL MEANS FOR HEATING SYSTEMS 6 Sheets-Sheet 5 Filed Aug. 8, 1950 f NNW Feb. 2,A 1954 E. B. TIDD CONTROL MEANS FOR HEATING SYSTEMS.

6 Sheets-Sheet 6 Filed Aug. 8, 1950 heat demands that occur on windy days during the heating season.

A further object is to provide an outdoor control for regulating a heating system in which the operation of a circuit controlling switch mechanism is determined by simultaneously exposing opposite ends of a heat conducting tube to the heating fluid and the outside air, the heat conditioning of the tube by these temperatures determining the extent of the control and the device being therefore responsive to outdoor temperature and wind variations.

A further object is to provide a control means as above indicated which is adjustable to establish a desired temperature of the circulating heating fluid to satisfy the heat demands of the space being heated in relation to any outdoor temperature.

This application is a continuation in part of my copending application for Heating System, Ser. No. 756,615, led June 24, 1.947, now Patent No. 2,526,755, January 2'?, 1.953..

These and further objects of the invention will be set `forth in Athe. following specification,y reference being had to the accompanying drawings and the novel means by which said objects are effectuated will be deiinitely pointed out in the claims.

In the drawings;

Fig. 1 is a schematic, isometric elevation of a one-pipe,y hot water heating system equipped in accordance with one phase of the invention and in which the circulating pump rens continuously during the heating season.

Fig. 2 is a diagrammatic, sectional elevation of a solenoid operated valve which operates as a flow control member in the system shown in Fig. 1.

Fig. 3 is an enlarged, sectional View of the outdoor control employed in Fig. 1.

Fig. 4 is a sectional elevation of a modified form Vof the control.

Fig. 5 is a section along the line 5--5 in Fig. 4.

Fig. 6 is an enlarged section along the line E--lv in Fig. 4.

Fig. 7 is an enlarged, fragmentary section of the control means as viewed in Fig'. 4.

Fig. 8 is a view of the switch housing and associated parts looking in the direction of the arrow 8A in Fig. 4.

Fig. 9 is a sectional elevation of a portion of the Fig. 4 control showing the manner in which the switch wires are wrapped around the control when the latter is pushed through the building wall.

Fig. l0 is a sectional elevation of a further modied form of the control which utilizes a gas or liquid lled casing that is responsive to outside weather conditions and the heating uid.

Fig. 11 is a section along the line II-II in Fig. 10.

Fig. 12 is a sectional elevation showing a further modication using a gas or liquid filled casing as in Fig. 1G and associating this casing with a Bourdon tube and switching elements.

Fig. 13 is a fragmentary, sectional View showing a modiiied adjustment for the control illustrated in Figs. 4 and 7.

Referring to Figs. 1 and 2, the numeral I0 designates a hot waterl heating boiler from which leads a supply pipe II in which is interposed a flow control element in the form of an electrically operated valve, denoted. generally by the numeral t2. By way of. example, this valve is indicated as being of the solenoid operated type,

` Letters Patent,

' presently described.

but a motor operated valve may be used if desired, many types of the latter valve being well known in the art. On the discharge side of the valve I2, a pipe I3 connects the pipe II with the water inlet of an outdoor control Ill which extends through the building wall I5 a distance suflcient to insure that its outside extremity will be subject to weather changes, although as presently noted the position of the control is capable of being varied. rThe water outlet of the control i'r. is connected by a pipe I6 with the pipe I I, the water inlet and outlet being located inwardly oi the wall I5. To insure adequate water flow through the inner end of the control so that the regulating action of the latter will be accurate and substantial, the pipes I3 and I6 are connected to the pipe I I by ttings Il which are specially designed for one-pipe systems and embody the principles outlined in United States No. 1,663,271, dated March 20, 1925,

The pipe iis connected to any desired number of radiators, such as IB, and each radiator is connected by supply and return pipes i9 and 20 to the pipe II through fittings I'I for reasons noted in connection with the control I4. The return portion of the pipe II delivers the water to an electrically operated pump 2| whose discharge side is connected by a pipe 22 with the boiler and by a pipe 23 with the pipe H between the discharge side oi the valve I2 and the connection of the pipe I3 with the pipe II. Hence, when the valve I2 is closed, the pipe 23 serves as a bypass around the boiler I0, all water then being circulated through the pipe 23 by the pump 'ZI which runs continuously during the heating season.

Associated with the above piping is an electric circuit which includes the outdoor control Il as a part thereof and which will now be described. Power wires 2e and 25 are connected to a main switch 25 and :from the switch a wire 2l leads to the control I4 whose interior construction is more particularly illustrated in Fig. 3 and will be A wire 2t connects the control l4 with a room thermostat 29 positioned to be affected by the radiator 8 and a wire 30 connects the thermostat with a solenoid coil BI (see Fig. 2) operably related to the stem 32 of a valve element 33 which controls flow through the valve I2. The coil 3| is also connected by a wire 34 with the switch 26, the control I4, thermostat 29 and the electrical portion of the valve l2 being therefore arranged in series so that when the control and thermostat are closed, the valve I2 is open to permit hot water to now from the boiler.

Bridged around the Valve l2 is a circuit which includes in series relation a high limit. or safety aquastat 35 mounted in the boiler and respons sive to the boiler water temperature, and automatically operated, firing means 36a for the boiler which may be a gas or oil burner, or a mechanical Stoker. The aquesta-t 35 is connected by a Wire 3G with the wire 3Q, while a wire 3l connects the aquastat with the firing means and the latter is connected by a wire 38 with the switch 2E. Since the aquastat 35 is always closed under normal operating conditions, it will be obvious that the tiring means 35 will be operated simultaneously with the opening of the valve i2 when the thermostat 2t is closed since the firing means and the valve, respectively, are electrically in series with the thermostat 29 and the control I4.. Operation of the pump 2l is. de-

being heated, this condition is reiiected in a lown ered Water temperature at the inner .end ci' the control M Aand therefore a-contraction of the tube` 42. Hence, the control i4 again closes to cause sa fresh supply of hot water from the boiler .I

v.to enter the system, this supply being slightly tempered lby the relatively colder water moving l.through the bypass 23. Eventually, the rise in .system water temperature eiects an opening of the control lli with accompanying resul-ts as 1noted above. These repeated supplies of hot water from the boiler continue until the thermostat 29 is satisfied and thereafter heated water always courses through the system, thus eliminating .stratification `of air in the `space being heated and avoiding the possibility of a cold c 70 condition.

I-f the outdoor temperature drops to 0 the .firing means 3G will operate and the valve i2 will `open for longer periods to thereby establish the .higher water temperature required to satisfy the g.

increased heat demand inthe space and the control M before .the latter opens.

it is contemplated .that the thermo 2t would be used in well insulated buildings and might be omitted in those where the heat loss is 4more rapid and, in the latter case, the control .I4 Vwould Adetermine .directly :the operation of the valve vI2 .and the ringmeans 36.

The .foregoing .means of control eiectively an ticipates heat demands in .the space under all i Aweather wconditions and due to the principle .of coordinating heat conduction along the tube 152, it is characterized by the outstanding advantage relative to bulb systems of control of compensating for increased heat losses on windy days. Further, the control I4 is more compact than the I.bulb arrangement and is capable of easier .association with .a heating system.

In `Figs. 4 to i9, inclusive, is illustrated a modi- 'e'd form of the control, generally indicated by the numeral 58, which is characterized vby adjus'tability that enables the control to establish, in relation to any outdoor temperature, any desired temperature of the heating fluid within a reasonable range.

As before, .the control 158 extends through a building wall A59 and it includes an outside sleeve .150 whose length is vsufficient to .extend completely 'through the wall and which is preferably made 'of copper tubing because of its resistance to. C orrosion. Fitting within the sleeve 'iiilis a sleeve Bi `.which may be made from any of the commercial types of plastics and which extends for a convenient distance beyond the left, or inner, and the right, or outer, Vfaces of the wall, as viewed in Fig. 4.

A bushing 62 fits within the inner end of the sleeve .Bl `and is secured thereto by a set screw 63. This bushing is integrally formed with a heat block 64 which is located beyond the inner end of the sleeve El and is composed ci brass or 'other metal having an equivalent or a higher heat conductivity. An annular channel formed internally of the block 64 is bridgedby a copper sleeve 55 to thereby define an annular chamber 66, the sleeve 65 rbeing soldered or otherwise at- C) ca tached to the block for intimate heat exchange therewith and is concentric with the chamber 65 and the bushing 62. Pipes 61 and 6B., corresponding to pipes -I3 and I6 in Fig. 1, deliver and discharge, all respectively, hot water to and from the chamber 66 to thereby heat the block 64, including the bushing 62, and the sleeve 55.

The inner end of a brass control tube $9 is slidable within and in heat exchange relation to the sleeve 65, the inner extremity of the tube .59 being soldered to the reduced end of an adjusting screw it and an adjusting nut 'Il being threaded on the screw. The nut H is conditioned for a motion of rotation only by means of an annular Vgroove 'i2 formed peripherally therein and .in which fits ears 'I3-13 provided on laterally .extending, upper and lower arms 'I4- M integrally i'ormed with the heat block 64. To prevent rotation of the screw 10 when the nut H is rotated .and to restrict motion of the screw `to endwise movements only, the sides of the screw are atted, as at i5-l5, and these ats are engaged by a washer l5 which is apertured .to 'lit the flats. 'The washer it is located between the nut 7i and the heat block 'fi and peripheral "il-""5 on the washer embrace the side faces of the arms "ifi, A spring 'i8 encircles the control tube B9 between the block Gli and the washer T6 to maintain the latter in abutting relation to the nut il.

A copper, heat supply .sleeve 19, provided for a purpose presently explained, encircles the control tube 58 and is spaced therefrom for the major portion of its length. The inner end of the sleeve 'i9 slidably ts within the bushing l(i2 and, in the position of parts shown .in Figs. 4 and 7, iits closely around the sleeve t5, the bushing Vt2 and sleeve S5 being in heat exchange relation .ship with the indicated end of the sleeve '19. The opposite end of the sleeve lil, which is at .all .times included between the ends of the plastic sleeve 6l, is soldered to a brass bushing which in turn is .soldered to the control tube '69.

From the foregoing, it will vbe -understood that the heat supply sleeve 'I9 is anchored to the control tube 69 and moves endwise with the latter when the vnut 1I is rotated and that, when hot water is circulated through the chamber 66, heat .is supplied to the inner end of the control tube et through the sleeve E5 and to a part of the tube 6.9 remote from its inner end by way `of the bushing 62, heat supply sleeve 'i9 and bushing 8D.

The outer end of the control tube 59 projects .and is slidable through a seal ring 3| which vcloses the outer end of the sleeve Si and is soldered to a brass switch housing 82. The upper end of a lever 483 ris ,pivot'ed at B4 to the housing 82 and its lower end is operably related :to the plunger 85 of .a switch 3E which is of the same general character as 'the switch 5l in Fig. 3, except that in this case, an inward movement of the plunger relative to the switch opens the latter and an outward movement lcloses the switch. The free end oi the lever E3 can be adjusted with reference to the plunger 85 by means of an adjusting screw 81 carried by the lever and whose adjusted position is locked by a set screw 8B. Movements of the lever 83 towards the switch 85 are resisted by a spring 89 interposed between the lever and the casing of the switch. Adjacent the pivot 815, the lever t3 is apertured as at 90 and one end of an Invar rod 9i is pivoted within the aperture which is sized to permit rocking movements of the .lever relative to therod. The rod 9i extends through the controltube 69 'in spaced relation thereto and its inner end is firmly threaded in the adjusting screw 'i0 so that it moves with the control tube 69 when the latter is adjusted by the nut 'l I.

The switch 8E is fastened by screws 92 (see Fig.

8) to the housing 82 and wires s3 and 94, comparable to the wires 2? and 28 in Fig. 1, extend from the switch through passages 95-95 in the plastic sieeve 6|, only one passage being illustrated in Fig. 4, and thence through a connector 96 for connection to the electrical circuit illustrated in Fig. 1. The connector 26 is carried by a cup-shaped member 07 which is slipped over the inner end of the sleeve el and fastened thereto by a set screw 98. A cover 99 encloses the inner end of the control means, including the heat block 64 and is fastened to the member Si by means of a stud and a nut |0|. AY wall |02 may be clamped between the member 9i and cover 99 to separate the water pipes Si and $3 from the wires 93 and 94. The outer end of the plastic sleeve 6| carries a plastic disk |03 which is held in the position shown in Fig. 4 by a pin |04 carried by the disk and inserted in a pocket |54 in the wall 59. A metallic cover plate E65 is sealably carried by the disk |03 in enclosing and protecting relation to the housing Si and the parts carried thereby. The only purpose of the cover |05 is to protect the lever 83, switch 86 and Invar rod 9| against rain and the accumulations of snow and ice which might otherwise interfere with the free action of these parts as presently described. The temperature within the metal cover will always be substantially the same as the outdoor temperature and the presence of the cover will not interfere with the heat loss from the outer end of the control, including accelerated losses on windy days.

The operation of the control illustrated in Fig. 4 differs somewhat from that shown in Fig. 3 in that the lengthening and shortening of the control tube 69, in response to the mutual eifects of the circulating heating fluid and the outside temperature and general weather conditions including wind, causes a rocking of the lever 83 on the fixed pivot provided by the outer end of the rod 9| which has a zero expansion coefficient. A further difference resides in the fact that means are provided for regulating the quantity of heat supplied to the control tube 65 so that any desired temperature of the heating fluid, within a reasonable range, may be established in relation to any outdoor temperature.

The control is initially adjusted by means of the screw 8? with the parts otherwise in the positions shown in Fig. 4 so that when the entire control is exposed to a temperature of '72 F., which is a characteristic room temperature, the switch 85 will be open. At the place of installation, the member 97 and cover 99 are removed and the control is pushed through a hole in the wall 59 from the outside thereof. Prior to this insertion, the portions of the wires 93 and 94 which extend beyond the inner ends of the passages 95 are wrapped around the reduced, inner end of the sleeve 6|, as indicated by the numeral I0 in Fig. 9. Thereafter, the wires 93 and 94 are unwound, led through the connector 9E and attached to the remainder of the electrical circuit as shown in Fig. 1. The control is held against endwise movement by slipping a flange |07 over the inner end of the sleeve 60, suitably attaching the flange to the wall 59 and locking the flange to the sleeve 50 by a set screw |08. The member 91 is then mounted on the inner end of the sleeve 00, followed by the wall |02, and the pipes 6'! and 68 are connected to the heat block G4. The cover 99 is then Vfastened to the member 97, slots Ille-|09 being provided in the cover to clear the pipes Gl' and 62.

If the outdoor temperature at the time of installation is colder than that at which the control was initially adjusted, i. e., 72 the switch 86 will close to thereby open the flow control valve I2 and start the burner 3@ operating. The temperature of the fluid in the heating system will rise and the fluid will flow through the chamber et to thereby transfer heat to the heat block 54, including the bushing t2, and the sleeve t5. Hence, the control tube 59 receives heat in two locations, via., from the sleeve 65 and from the bushing Si! by way of the heat block bushing 52 and heat supply sleeve it. As indicated in Fig. 4, heat is transferred from the sleeve t5 to the tube t9 a short distance from the end of the latter in the position of parts illustrated, which distance may be of the order of 1A, while the sleeve 19 has maximum area contact with the bushing S2 and so has transferred thereto the maximum amount of heat available.

The heat transferred through the indicated dual paths to the control tube 69 causes the latter to lengthen and further shift the lever pivot 30 outwardly with respect to the pivotal connection or' the lever 03 to the rod 9|, thus rocking 'the lower of the lever towards the switch plunger 85. if this first run of the control results in an opening of the switch 86 before the temperature of the heating fluid has been raised sufficiently to adequately heat the space being serviced, the nut H is rotated a turn or two to shift the control tube 59 and heat supply sleeve EQ towards the right, as viewed in Fig. 4.

This adjustment achieves two purposes with respect to the heat conditioning of the control tube 69. First, heat is applied through the bushing t5 closer to the left end of the tube 69 so that this portion of the heat must travel a longer distance before being subjected to the chilling action of the colder end of this tube, and, second, shifting of the heat supply sleeve 19 towards the right reduces its area of contact with the heat block bushing 62 and hence the amount of heat transferred to the tube S9 through the sleeve 19. The joint result of these two conditions is that a higher temperature must be established in the heating fluid before sufficient heat is transferred to the tube 69 to open the switch. Still higher fluid temperatures may be secured by further rotating the nut 1| in the indicated direction up to the limit of the adjustment when the inner end of the heat supply sleeve 'i9 separates from the bushing 62. At this point and just prior thereto, it will be noted from Figs. 4 and 7 that the left end of the control tube 69 will have been drawn within the bushing 65 to thereby reduce the heat transfer area between the tube and bushing.

The heat supply sleeve is an important feature of the invention for it enables the control tube to be supplied with heat at a point remote from the primary heat supply, namely, the bushing 65, and closer to the heat dissipating end of the control. This characteristic insures that the switch 36 can be opened with lower temperatures of the heating fluid and yet have such temperatures suiciently high for space heating purposes. For fuel economy, it is important that the temperature of the circulating uid be maintained as low as possible as long as it heats the space. An ancillary advantage of the sleeve 'I9 is that since under normal conditions, it is always heated, it reduces radiant losses from the control tube 69.

As with the control shown in Fig. 3, this control anticipates heat demands under all weather conditions, including wind, but possesses superior qualifications in respect of adjustability and capacity to lower temperatures of the heating fluid.

Where parts in the Fig. 4 control are indicated as being made of copper or brass, it will be understood that such designation is inclusive of other metals having equal or higher heat conducting properties.

In Figs. 10 and li is illustrated a variant form of outdoor control. This modiiication is similar to the controls described above in that it utilizes the coordinating action of variations in the out door and heating system fluid temperatures as applied to a heat conducting casing, but differs therefrom in that the temperature variations of the casing reflected in pressure changes in a fluid sealed in the casingy or tube which affect a diaphragm actuated switch.

Specifically, this modification comprises a heat conducting tube iid, similar to the tube 42, which entends through. a building wall i I and is preferably insulated therefrom by a sleeve |i2. A substantial portion of the tube projects beyond the outer surface of the wall for exposure e to the outside weather and its outer extremity is closed by a plug i3. It will be understood, however, that the control tube its may have its position adjusted as described for the tube it. The

inner end of the tube i iii is mounted in an open f top housing i Hi located inwardly of the wall i ii and which includes a chamber H5 that com municates with the interior of the tube. The top oi the housing |44 is closed by a diaphragm Ht clamped thereagainst by a frustoconical cover ||1 and the tube llt and chamber H5 are lled with a suitable gas or liquid sealed in at any desired temperature and pressure. Hence, the diaphragm i6 is responsive to pressure changes in the fluid in the tube ii). Air may be used as a fill, or any of the well known, heat expansible liquids which will not freeze at any of the outdoor temperatures to which the control might be subjected. Bridged across the chamber ||5 and in heat exchanging relation with the fluid therein is a tube HS (see Fig. '11) which is preferably composed of copper or a comparable heat conducting metal and which communicates with the ends of pipes H9 and i220 mounted in the housing liti and which pipes may be connected to the heating system in accordance with the arrangement shown in Fig. l.

A threaded stem i2| is fixed to the central part of the top surface of the diaphragm H6 and adjustable on the stem is a nut |22 having an extension |23 which is reciprocable through a hole |24 in the cover ||1 and moves with the diaphragm. Th extension |23 is intended to actuate a snap switch i25 which is preferably of the same general type as switch 51, except that upward movement of the diaphragm H5, correa spending to a lessened demand for heat, effects an opening of the switch |25, while a contrary movement, corresponding to an increased demand for heat, effects a closing of the switch.

The switch |25 comprises a housing |26 composed of insulating material and through whose bottom is slidably mounted a plunger |21 which is actuated upward by the extension |23. The upper end of the plunger is operably related to trated in Fig. l1.

1.2 an electrically conducting, spring leaf |28 whose left end is secured to a shim |29 which abuts the cover of the housing |26 by means of a screw |30 in conducting relation to the spring leaf 28 and a wire |3| is connected to the screw. integrally formed with the opposite or free end of the spring leaf |28 and extending in spaced relation on opposite sides and towards the fixed end of the leaf is a pair of members |32, each of which is shaped in the manner shown in Fig. il, and the free end of each member freely seats within a socket |33 in the shim |29 so that the members may rock upwardly and downwardly relative to the shim. Only one of the members |32 is illus- The switch is shown in closed position with the free end of the spring leaf |28 resting on a metallic block |34 secured to the bottom of the housing |26 by a screw |E which is in electrically conducting relation to the block and to the screw one end of a wire |36 is connected. When the plunger |21 is moved upwardly, the spring leaf |28 is snapped upwardly to place its free end in contact with a block |31 secured to the cover of the housing |25 which is the open circuit position of the switch. This movement of the leaf spring |23 is permitted by a slot |31a cut in the shim |29 which provides clearance for the flexing of the spring. When pressure on the plunger |21 is relieved sufficiently, the spring leaf |28 automatically returns to the closed circuit position shown in Fig. l1. For further structural details of the switch |25 and the theory of its operation, reference may be had to the last noted patent.

The control shown in Figs. l0 and ll may be used with the heating system shown in Fig. i, the wires |3| and IBS being connected to the electrical circuit of the latter figure in the same manner as the wires 28 and 21. This control performs the same function in relation to a heating system as does the controls shown in Figs. 3 and 4 and its general characteristics are the same, except that regulation is eifected by pressure changes in the fluid enclosed in the tube ||0 as the heat conditioning thereof varies with fluctuations in the temperatures, outdoor and heating medium, to which it is simultaneously subjected. Adjustment of this control is secured by the nut |22 and by varying the length of the tube ||0 that is exposed outdoors.

A further form of outdoor control is illustrated in Fig. l2 which is similar to that shown in Figs. 10 and 11 in that control is exercised by pressure changes in a heat expansible fluid enclosed in a heat conducting tube subjected to the outside weather and the circulating fluid of the heating system, but diifers therefrom in that the tube is associated with an extension in the form of a Bourdon tube whose free end is connected to a circuit controlling switch.

Referring to Fig. 12, the numeral |38 designates a heat conducting tube which extends through and projects beyond opposite sides of a building wall |39 and is insulated therefrom by a sleeve |40. The outer or weather end of the tube is closed and the opposite end extends through a housing |4| whose opposite ends are closed by plugs |42 and |43 which encircle the tube. Between the plugs, the housing |4| is annularly chambered, as at |44, and through this chamber ows heating system fluid in heat exchanging relation to the tube |38, the uid being supplied and evacuated through pipes |45 and |46, respectively, which may be connected to the heating system as shown in Fig. 1.

The tube |38 extends beyond the plug |43 and is secured to one end of a Bourdon tube |41, this end therefore constituting the xed end of the Bourdon tube whose interior communicates with the interior of the straight tube |38. rIhe Bourdon tube may be enclosed in a suitable housing |48 and its free end is connected to one end of a metallic switch lever |49 pivoted at |50 in the housing. The lever carries an electrical contact which when the lever is rocked to a closed position engages a xed contact |52 supported by the housing |48. A fixed magnet |53, also carried by the housing, is disposed adjacent the free end of the lever to accelerate its movement in a direction to engage the contacts I5! and |52.

Wires |54 and |55 connect the fulcrum |56 and the fixed contact |52, respectively, to the electrical circuit shown in Fig. 1. Since the disclosure of the switch mechanism in the housing |48 is largely diagrammatic, it will be understood that the pivot |50, contact |52 and magnet |53 will be suitably insulated from thehousing, and the lever |49 will also be insulated from the connected end of the Bourdon tube |41.

The straight tube |38 and the Bourdon tube |41 are filled with a suitable gas or liquid which is sealed in the indicated members and its operating characteristics therefore will be similar to the Fig. type, but modied by the Bourdon tube |41. The circuit controlling lever |49 is shown in open position indicating satisfied heat demand in the space being heated. When the fluid in the tube |38 and the Bourdon tube |41 chills sufliciently to effect a contraction of the Bourdon tube, the lever |49 will be rocked to close the contacts |5| and |52 and the ensuing action will through the associated electrical circuit effect a resumption of the heat supply. Otherwise, the characteristics of this modification in relation to the heating system and its ability to coordinate the effects of outside Weather, including wind action, and the heating uid temperatures on a heat conducting tube are identical with the other forms above described. It is contemplated that the Fig. 12 modication, due to the use of a Bourdon tube and the connected lever, may be characterized by an increased mechanical advantage for the purpose of circuit control, relative to the form shown in Fig. 10. Adjustment is effected by varying the length of the tube |38 exposed to the outside weather as already noted. The Bourdon tube is regarded as the equivalent of any extensible chamber, such as a bellows, which encloses a uid and one end of which is free to move in response to pressure variations in the uid.

In Fig. 13 is illustrated a modified arrangement for adjusting the control shown in Figs. 4 and 1 and wherein like parts in these figures are identied by the same numerals.

An Invar rod |55, corresponding to the rod 9|, extends through the control tube 69 in the manner described above and its left or inner end is threaded through a plug |51 mounted in the adjacent end of the tube 69. The threaded end of the rod S is continued through an adjusting nut |58 having an annular boss |59 which is journaled in upper and lower arms ||6ll integrally formed with and extending laterally from the heat block 34. An annular groove |5| is formed in the boss |59 and fitting within the groove are the ends of a plurality of screws |62 which are threaded through the arms |60. Hence, the nut |58 is conditioned for rotation only to thereby advance or retract the rod |56 which 14 imparts like movements to the control tube 69 and heat supply sleeve 19 since the rod |56 does not rotate within the plug |51.

A heating system which is associated with any of the above outdoor controls will be conditioned to maintain an indoor temperature that is satisfactory for maximum body comfort. A substantial balance is maintained between heat supply and heat loss and there is always a sufficient amount of heat in the radiators to insure circulation of warm air in the room, thus preventing stratification. Closer regulation of the desired temperature in the room is therefore possible, as compared with the present indoor system of conq trol, and heat demands which obviously vary with changes in the Weather are efficiently handled by my improved control which anticipates the interior requirements for heat. Moreover, stand-by heat losses of the boiler are held to a minimum because the firing periods of the firing means are elastieally related to the demands for heat in the space being heated, lower temperatures in the boiler being possible on mild days than. on colder days, thus enabling certain economies in overall operation.

An outstanding feature of the invention is the use of a heat conducting tube as the correlating factor between the outside temperatures and those of the heating fluid. The use of such a tube enables the structure to respond to increased heat demands on windy days since the dissipation of heat along the tube will clearly be greater than on still days even though the respective outdoor 'temperatures are identical. This variation in heat dissipation or rate of heat loss heat conditions the tube to provide the required control, regardless of the type employed. The controls above described are not restricted to the continuous flow heating system shown in Fig. l, nor to the specic electrical circuits illustrated, but may aise be used with systems employing intermittent flow and with other electrical circuits.

Where any of the above controls are used with a hand fired system, they would be connected to the boiler or furnace dampers for regulating the burning rate of the fuel.

I claim:

l. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a heat conducting tube having one end subjected to outdoor Weather, means for simultaneously supplying heat from the heating medium to limited area portions of the opposite end and an intermediate part of the tube, means for varying the amount of heat sup-l plied to the intermediate tube part to thereby vary the total amount of heat supplied to the tube, and means responsive to length changes in the tube effected by the heat supplied thereto and weather conditioning thereof for determining the supply of heat to the space.

2. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor Weather conditions comprising a heat conducting tubel having one end subjected to outdoor weather," means for simultaneously supplying heat from the heating medium to limited area portions of the opposite end and an intermediate part of the tube, means for simultaneously varying the amounts of heat supplied to said vopposite end and intermediate part to thereby vary the total amount of heat supplied to the tube, and means responsive to length changes in the tube effected Y15 by the heat supplied thereto and weather 'conditioning thereof for determining the supply of heat to the space.

3. Control means for a heating system for mantainin-g the temperature of the space to be heated in relation to varying outdoor weather conditions comprising` a nrst heat conducting tube having one end subjected to outdoor weather, a heat block through which the heating medium is, circulated in heatv exchange relation to the opposite end of the tube, a second heat conducting tube surrounding the rst tube, the opposite ends. of the second 'tube being in heat exchange relation to the heat block and an intermediate part of the iirst tube, respectively,v and means responsive to length changes in the rst tube ef fected by the total heat supplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

4. Control means for a heating system for maintaining the temperature of the, space. to be heated in relation to varying outdoor Weather conditions comprising a iirst heat conducting tube havingA one end subjected to outdoor weather,

a heat block through which the heating mediumv f' is, circulated in heat exchange relation to the opposite end of the tube, a second heat conducting tubesurrounding the first tube, the opposite ends of the second tube being in heat exchange relation to the heat block and an intermediate part of. the iirst tube, respectively, means for varying the area Contact of the second tube with the heat block to thereby vary the total amount of heat supplied to the first tube from the heat block, and meanstresponsive to length changes in the rst tube eliected by the total heat supplied thereto and the Weather conditioning thereof for determining the supply of heat tothe space.

5. Control means for a. heating system for maintaining the temperature of the space to be heated in relation to varying outdoor Weather conditions comprising a rst heat conducting tube having one end subjected to outdoor Weather, a heat` block through which the heating medium is circulated in heat exchange relation to the opposite end of the tube, a second heat conducting tube surrounding the first tube and having one end fastened in heat exchange relation to an intermediate part of the first tube, the opposite, end of the second tuber being in heat exchange rela-tion to. the heat blocla, means for shifting thel first tube endwise to thereby vary the areas of contact between the heat block and rst and second tubes,v respectively, and the total amount of heat supplied to the first tubev from the heat block, and meansV responsive to length changes in the rst tube effected by the'total heat supplied thereto andthe Weather conditioningthereoi for determining the supply of heat to the space.

6. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a nrst heat conducting tubeA having one endY subjected to outdoorr weather, a heat block through which the heating medium is circulated in heat exchange relation to theA opposite end oi' the tube, a second. heat. conducting tube surrounding the first tube, theA opposite ends, of the second tube beingy in heat exchange relation to the heat block and an inter mediate part o the first tube, respectively, both tubes being composed of a material having a relatively high coeilicient of expansion, a rod composed' ofv a material having a substantially zero coeiicient ci expansion extendingl through the first tube in spaced relation thereto and having one end secured to the heat block end of the first tube, and electrical switch means operably related to the other end of the rod and the end or the first tube adjacent thereto, the switch means being responsive to changes in length of the iirst tube eliected by the heat supplied thereto and the weather `conditioning Ithereof for deterruining the supply of heat to the space.

'7. Control mea-ns for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a first heat conducting tube having one end subjected to outdoor Weather, a heat block through which the heating medium is circulated in heat exchange relation with the opposite end of the tube, a second neat conducting tube surrounding the irst tube and having one end fastened in heat exchange relation to an intermediate part of the iirst tube, the opposite end oi' the second tube being in heat exchange relation with the heat block, both tubes being composed' ci a material havinfr a relatively high coefficient of expansion, a rod ci .nposed of a material having a substantially :nero coefficient of expansion extending through the iirst tube in spaced relation thereto and having one end secured tothe heat block end of the first tube, means for shitting the .iirst tube endvvise to thereby vafv the areas of contact between the heat block and first and second tubes, respective-ly, and the total amount of heat supplied to the rsttube from the heat block, and electrical switch means op ably related to the other end of the rod the end ofthe rst tubo adjacent thereto, the switch means being responsive to changes in length of the iirst tube effected by the supplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

8. Control means for a heating system for maintaining the temperature oi the space to be heated in relation to varying outdoor Weather conditions comprising a nrst heat conducting tube having one end subjected to outdoor weather, a heat lJloclz through which the heating medium is circulated, the opposite end of the first tubebeing slidable through and in heat exchange relation to the heat block, a second heat conducting tube surrounding the 'irst tube and having oneend fastened in heat exchange relation to an intermediate part o1" the first tube, the opposite end of the second 'tube being slidably mounted on and in heat exchange relation to the heat block,y means ier shifting the iii-st tube endwise to thereby vary the areas of contact between the heat block and first and second tubes, respectively, and the total amount of heat supplied to the rst tube from the heat block, and means responsive to length changes in the first tube effected by the total heat supplied thereto, and the weather conditioning thereof for determining the supply of heat to the space.

9. Control means or a heating system for maintaining the temperaturev of the space to be heated in relation to varying outdoor weather conditions comprising a heat conducting tube. having one end subjected 'to outdoor Weather, a heat block through which the heating medium is circulated in heat exchange relation to the opposite end ci the tube, a second heat conducting tube surrounding the first tube, the opposite ends of they second tube being in heat exchange relation to the heat block and an intermediate part'of the first tube, respectively, means for shifting the rst tube endwiseto vary the heat travel distance between the heat block and the weather end of the iirst tube, means for varying the area contact of the second tube with the heat block to thereby vary the amount of heat supplied to the first tube by the second tube, and means responsive to length changes in the first tube effected by the heat supplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

10. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a first heat conducting tube having one end subjected to outdoor weather, a heat block through which the heating medium is circulated in heat exchange relation lto the opposite end of the tube, a second heat conducting tube surrounding the rst tube, the

opposite ends of the second tube being in heat exchange relation to the heat block` and an intermediate part of the first tube, respectively, means lfor simultaneously shifting the first and second tubes endwise in the same direction, the shifting of the first tube varying the heat travel distance between the heat block and the weather end of the first tube and the shifting of the second tube varying the area contact thereof with the heat block to thereby vary the amount of heat supplied to the first tube by the second tube, and

means responsive to length changes in the first tube effected by the heat supplied thereto and the weather conditioning thereof for determining' the supply of heat to the space.

1l. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a rst heat conducting tube having one end subjected to outdoor weather, a

lieatblock through which the heating medium is circulated in heat exchange relation to the opposite end of the tube, a second heat conducting tube surrounding the first tube, the opposite ends of the second tube being in heat exchange relation to the heat block and an intermediate part s;

spaced relation thereto and having one end secured to the heat block end of the first tube, means for shifting the first tube endwise to vary the heat travel distance between the heat block and the weather end of the first tube, means for varying the area contact of the second tube with the heat block to thereby vary the amount of heat supplied to the first tube by the second tube, and electrical switch means operably related to the other end of the rod and the end of the first tube adjacent thereto, the switch means being responsive to changes in length of the first tube effected by the heat supplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

12. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a rst heat conducting tube having one end subjected to outdoor weather, a heat block through which the heating medium is circulated in heat exchange relation to the opposite end of the tube, a second heat conducting tube surrounding the first tube, the opposite ends of the second tube being in heat exchange relation to the heat block and aniintermediate4 part of the first tube, respectively, both tubes being composed of a material having a relatively high coeiiicient of expansion, a rod composed of a material having a substantially zero coefficient of expansion extending through the first tube in spaced relation thereto and having one end secured to the heat block end of the first tube, means for simultaneously shifting the first and second tubes endwise in the same direction, the shifting of the rst tube varying the heat travel distance between the heat block and the weather end of the first tube and the shifting of the second tube varying the area contact thereof with the heat block to thereby vary the amount of heat supplied to the first tube by the second tube, and electrical switch means operably related to the other end of the rod and the end of the first tube adjacent thereto, the switch means being responsive to changes in length of the first tube effected by the heatsupplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

13. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a first elongated, heat conducting member having one end subjected to outdoor weather, a heat block through which the heating medium is circulated in heat exchange relation .to opposite end of the member, a second elongated, heat conducting member positioned adjacent to the first member, the opposite ends of the second member being in heat exn change relation to the heat block and an intermediate part of the first member, respectively, means for shifting the first member endwise to vary the heat travel distance between the heat block and the weather end of the first member, means for varying the area contact of the second member with the heat block to thereby vary the amount of heat supplied to the first member by the vsecond member, and means responsive to length changes in the first member effected by the heat supplied thereto and the weather con'.- ditioning thereof for determining the supply of heat .to the space.

14. Control means for a heating systemnfor maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a first elongated, heat com ducting member having one end subjected to out door weather, a heat block through which the heating medium is circulated in heat exchange relation to the opposite end of lthe member, a second elongated, heat conducting member positioned adjacent to the first member, the opposite ends of the second member being in heat exchange relation to the heat block and an intermediate part of the first member, respectively, means for simultaneously shifting the first and second members endwise in the same direction, the shifting of the first member varying the heat travel distance between the heat block and the weather end of the first member and the shift of the second member varying the area contact thereof with the heat block to thereby vary the amount of heat supplied to the first member by the second member, and means responsive to length changes in the first member effected by the heat supplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

15. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a rst elongated, heat conducting member having one end subjected to outdoor Weather, a heat block through which the heating medium is circulated in heat exchange relation to the opposite end of the member, a second elongated, heat conducting member positioned adjacent the rst member, the opposite ends of the second member being in heat exchange relation to the heat block and an intermediate part of the rst member, respectively, both members being composed of a material having a relatively high coeiicient of expansion, a rod composed of a material having a substantially cero coefeient oi expansion extending along the ilrst member in spaced relation thereto and having one end secured to the heat block end of the first member, means for shifting the rst member endwise to vary the heat travel distance between the heat block and the Weather end of the first member, means for varying the area contact of the second member with the heat block to thereby vary the amount of heat supplied to the rst member by the second member, and electrical switch means operabl'7 related to the other end of the rod and the end of the first member adjacent thereto, the switch means being responsive 'to changes in length of the rst member effected by the heat supplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

16. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising a nrst elongated, heat ccnducting member having one end subjected to outdoor weather, a heat block through which the heating medium is circulated in heat exchange relation to the opposite end of the member, a second elongated, heat conducting member positioned adjacent the first member, the opposite ends of the second member being in heat exchange relation to the heat block and an intermediate part of the rst member, respectively, both members being composed of a material having a relatively high coefficient of expansion, a rod composed of a material having a substantially zero coefficient of expansion extending along the first member in spaced relation thereto and having one end secured to the heat block end of the first member, means for simultaneously shifting the first and second members endvvise in the same direction, the sluiting i the rst 'member varying the heat travel distance between the heat block and the weather end-ot the first member and the shifting of the second member varying the area contact thereof with the heat block to thereby vary the amount of heat supplied to the first member by the second member, and electrical switch means operably related to the other end of the rod and the end of the iirst member adjacent thereto, the switch means being responsive to changes in length of the rst member effected by the heat supplied thereto and the weather conditioning thereof for determining the supply of heat to the space.

17. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor weather conditions comprising an elongated, heat conducting member having one end subjected to outdoor weather, means for simultaneously supplying heat from. the heating medium to limited area portions of the opposite end and an intermediate part of the member, means for varying the amount of heat supplied to the intermediate member part to thereby vary the total amount o heat supplied to the member, and means responsive to length changes in the member effected by the heat supplied thereto and weather conditicning thereof for determining the supply of heat to the space.

18. Control means for a heating system for maintaining the temperature of the space to be heated in relation to varying outdoor Weather conditions comprising an elongated, heat conducting member having one end subjected to outdoor weather, means for simultaneously supplying heat from the heating medium to limited area portions of the opposite end and an intermediate part oi the member, means for simultaneously varying the amounts of heat supplied to said opposite end and intermediate part to thereby vary the total amount of heat supplied to the member, and means responsive to length changes in the member effected by the heat supplied thereto and Weather conditioning thereof for determining the supply of heat to the space.

EDWIN B. TIDD.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,358,073 Fulton Nov. 9, 1920 1,969,968 Dever Aug. 14, 1934 1,981,679 Stem Nov. 20, 1934 2,290,985 McElgin July 28. 1942 

